Ushio AL-1824 / Welch Allyn 09500 18-24W MFI/VDX HID Metal Halide Lamp

The Short Arc Gap
USHIO’s Sōlarc single-ended lamps allow the equipment designer to capitalize on the lamp’s unique short arc length. At 1.27mm, with a peak luminance at the cathode, the lamp begins to approximate a point source. Coupled with carefully designed lenses or reflectors with maximum light capture and the appropriate focus, the lamp can deliver high-intensity light to tightly controlled or divergent beam applications. The figure below shows the luminous intensity distribution of the arc. The two sources of peak intensity lie near the electrode tips.

Highest Efficacy
Metal halide lamps are inherently very efficient, providing two to three times the efficacy of either halogen or xenon lamps. Optimizing the optical system using the short arc can provide an efficiency increase in many applications, allowing the Sōlarc lamp to deliver as much light as a halogen lamp with four to five times more wattage. High efficacy plus the resultant decreased demand for power allow the equipment designer to develop miniature, lighter weight, portable and even battery-powered product configurations.

Bright White Light
Sōlarc lamps inherently exhibit a correlated color temperature comparable to the sun of 5,000K–7,000K. Halogen lamps normally operate in the 3,000°K–3,200°K range and vacuum incandescent lamps in the 2,600K–2,900K range. In visible terms, the lower color temperature dictates more red or yellow in the light. The higher color temperature enables realistic visualization of color rendering and contrast. While it is possible to operate halogen lamps up to 4,300K by the use of filters, it is at the expense of severely reducing the lamp’s light output and life. The daylight color temperature of the Sōlarc lamp produces a whiter, “cooler” light, which reproduces the full range of colors. The output is color balanced, making it ideal for use with CCD video cameras.

Excellent Light Maintenance
Unlike many metal halide lamps, Sōlarc lamps maintain much of their intensity and color balance throughout their life. In applications requiring white light, the life of the Sōlarc lamp could be many times that of a competing halogen lamp. Typically our lamps will maintain 75% of their initial intensity. Shifts in X and Y chromaticity values are typically less than 1.5%.

Lamp life is defined as a rated median life with a duty cycle of one hour on and 15 minutes off for 19, 22 and 25W lamps. The median life is the time at which 50% of the lamps are still operational. An application requiring a duty cycle with a longer “on” time for each start will extend the life, and shorter “on” times will reduce lamp life. The predominant symptom of end of life will be failure of the lamp to start.